The "unearthly" strains of Ron Grainer's soon-to-be-famous title music announced the arrival of Doctor Who to British TV screens on Saturday, November 23, 1963. It must have been quite a baffling experience for first-time viewers: the swirling abstract graphics, the weird electronic sound effects courtesy of the BBC's Radiophonic Workshop, the very oddity of the show's title. This really was groundbreaking TV. "I think you'll find there's a very simple explanation for all of this", says schoolteacher Ian Chesterton (William Russell) condescendingly, shortly before being taken on board the TARDIS and transported to an alien planet. For audiences, too, this was something entirely unfamiliar, yet obviously appealing: Doctor Who ran for almost 30 years and remains one of the BBC's most popular shows. His later incarnations were all eccentric in their different ways, but William Hartnell's original Doctor is an irascible and distinctively alien character, not at all happy having to put up with ignorant 20th-century humans. The "Unearthly Child" of the title is his granddaughter Susan (Carole Ann Ford), temporarily attending school on Earth. She is conspicuously different from her classmates and attracts the attention of two of her teachers who resolve to find out why. After an encounter with her mysterious grandfather they are whisked away on an adventure to a different time and place where angry cavemen are trying in vain to learn the secret of fire. Thus the show's trademarks are established from the outset: the Doctor and his more or less reluctant human companions, the mechanical unreliability of the TARDIS, the cliffhanger ending of each episode. It was a formula that rarely changed but that allowed apparently limitless variation, the only constraint being the BBC's budget. In later years the show tried vainly to compete with blockbuster special effects movies; but its original low-key incarnation relied more on inventive scenarios and good writing--qualities that are just as important now as then. --Mark Walker

The Daleks (sometimes called "The Dead Planet") is the second-ever Doctor Who serial. First broadcast between December 1963 and February 1964, the seven-episode story ensured the program's success by introducing the Doctor's most iconic enemies. Five hundred years after a nuclear war has devastated the planet Skaro, the Doctor (William Hartnell), Barbara, Ian, and Susan materialize in a petrified forest where the pacifist, and decidedly camp, Thals face starvation. Our heroes visit a nearby city, the home of the last remaining Daleks, terrifyingly cold-blooded mutants encased in armed, pepper-pot-like shells, and become involved in a desperate battle for survival. Given a nightmarish atmosphere by Tristram Cary's surreal electronic score, The Daleks proved the template for many a future Doctor Who adventure. Hartnell's Doctor is a surprisingly self-serving hero and the ambitious storytelling, which reflects the Cold War fears of the time, belies a tiny budget. The remastered picture sometimes looks digitized, but this story, remade for the cinema as Dr. Who and the Daleks (1965) and starring Peter Cushing, is still both an effective, if at times unintentionally hilarious, entertainment and an essential piece of television history. A superior sequel, The Dalek Invasion of Earth, was screened in late 1964. --Gary S Dalkin

One of the rarest of the early Doctor Who series, with William Hartnell as the crusty old Doctor, Edge of Destruction is entirely based in the TARDIS, which has stopped somewhere between worlds and times. The Doctor blames Ian and Barbara, the two teachers who came aboard in search for answers about his granddaughter, Susan, assuming they have committed sabotage in an attempt to return to their own time. They, in turn, in spite of recent shared escapes from Cavemen and Daleks, have no particular reason to trust his sanity. Something is causing one after another of them to act with violent irrationality, and the clock is ticking towards their destruction... This is a claustrophobic two-episode plot in which the series examines closely some of its more beloved assumptions. --Roz Kaveney